Adapter, extension, and connector assemblies for surgical devices

ABSTRACT

An adapter assembly for connecting an end effector to an electrosurgical instrument is provided. The adapter assembly includes a drive transfer assembly, first and second pusher assemblies, a drive member, an extension assembly, and a trocar assembly. The drive transfer assembly includes first, second and third rotatable shafts. Each pusher assembly is operably connected to a rotatable shaft for converting rotational motion from one rotatable shaft to longitudinal movement to perform a different function. The drive member is operably connected to the third rotatable shaft for transferring rotational motion from the third rotatable shaft to perform a third function. The extension assembly is operably connected to a distal end of the adapter assembly and includes at least one flexible band assembly operably connected to one of the first and second pusher assemblies. The trocar assembly is configured for releasable engagement with the extension assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/145,759 filed Apr. 10, 2015, the entire disclosure of which is incorporated by reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates generally to powered surgical devices. More specifically, the present disclosure relates to adapter and extension assemblies for selectively connecting end effectors to the actuation units of the powered surgical devices.

2. Background of Related Art

Powered devices for use in surgical procedures are known. To permit reuse of the handle assemblies of these powered surgical devices and so that the handle assembly may be used with a variety of end effectors, adapter assemblies and extension assemblies have been developed for selective attachment to the handle assemblies and to a variety of end effectors. Following use or following a useful life, the adapter and/or extension assemblies may be disposed of along with the end effector. In some instances, the adapter assemblies and extension assemblies may be sterilized for reuse.

SUMMARY

The present disclosure relates to an adapter assembly for connecting an end effector to an electrosurgical instrument. The adapter assembly includes a drive transfer assembly, first and second pusher assemblies, a drive member, an extension assembly, and a trocar assembly. The drive transfer assembly includes first, second and third rotatable shafts. Each pusher assembly is operably connected to a rotatable shaft for converting rotational motion from one rotatable shaft to longitudinal movement to perform a different function. The drive member is operably connected to the third rotatable shaft for transferring rotational motion from the third rotatable shaft to perform a third function. The extension assembly is operably connected to a distal end of the adapter assembly and includes at least one flexible band assembly operably connected to one of the first and second pusher assemblies. The trocar assembly is configured for releasable engagement with the extension assembly.

In disclosed embodiments, the adapter assembly further comprises at least one retention member, for example a first retention member and a second retention member, configured to releasably couple the trocar assembly with the extension assembly. It is disclosed that each retention member is configured to engage a flat portion of the trocar assembly, the first retention member is configured to engage the second retention member, and that the second retention member is configured to engage the first retention member.

It is also disclosed that the retention member includes a nub configured to releasably engage a respective detent of the trocar assembly.

Additionally, it is disclosed that the extension assembly defines a longitudinal axis, and that the retention member is movable in a direction perpendicular to the longitudinal axis through an opening of the extension assembly and into engagement with the trocar assembly.

The present disclosure also relates to an electromechanical circular stapling instrument including a handle assembly, an elongated portion extending distally from the handle assembly and defining a longitudinal axis, a trocar assembly including a distal tip for penetrating tissue, and first and second retention members configured to releasably couple the trocar assembly with the elongated portion. The trocar assembly is configured for releasable engagement with the elongated portion. The retention members are configured to engage a flat portion of the trocar assembly. The first retention member is configured to engage the second retention member, and the second retention member is configured to engage the first retention member. It is further disclosed that each of the first retention member and the second retention member is configured to engage a flat portion of the trocar assembly.

In disclosed embodiments, the retention members include a nub configured to releasably engage a respective detent of the trocar assembly.

It is also disclosed that the retention members are movable in a direction perpendicular to the longitudinal axis through an opening of the elongated portion and into engagement with the trocar assembly.

The present disclosure also relates to a method of securing a trocar assembly to an elongated portion of a surgical instrument. The method includes inserting a portion of a first retention member through a first opening in an outer wall of the elongated portion of the surgical instrument, inserting a portion of a second retention member through a second opening in the outer wall of the elongated portion of the surgical instrument, engaging the portion of the first retention member with a first flat portion of the trocar assembly, engaging the portion of the second retention member with a second flat portion of the trocar assembly, and engaging the first retention member with the second retention member.

In disclosed embodiments, the method also includes engaging a nub of the first retention member with a first detent of the trocar assembly and engaging a nub of the second retention member with a second detent of the trocar assembly.

It is further disclosed that engaging the first retention member with the second retention member includes inserting an extension portion of the first retention member at least partially within a receptacle of the second retention member, and that the method also includes inserting an extension portion of the second retention member at least partially within a receptacle of the first retention member. It is also disclosed that inserting the extension portion of the first retention member at least partially within the receptacle of the second retention member and inserting the extension portion of the second retention member at least partially within the receptacle of the first retention member occur simultaneously.

In disclosed embodiments, inserting the portion of the first retention member through the first opening in the outer wall of the elongated portion of the surgical instrument includes moving the first retention member in a direction perpendicular to a longitudinal axis defined by the elongated portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure are described herein with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective separated view of an adapter assembly, in accordance with an embodiment of the present disclosure, an extension assembly, in accordance with an embodiment of the present disclosure, and an exemplary handheld electromechanical surgical device;

FIG. 2 is a perspective side view of the exemplary handheld electromechanical surgical device of FIG. 1;

FIG. 3 is a perspective side view of the adapter assembly of FIG. 1;

FIG. 4 is a perspective side view of the adapter assembly of FIG. 3 with the outer sleeve removed;

FIG. 5 is a perspective side view of the adapter assembly of FIGS. 3 and 4 with proximal and distal housings of first and second pusher assemblies removed;

FIG. 6 is a cross-sectional side view of the adapter assembly of FIGS. 3-5 taken along line 6-6 in FIG. 3;

FIG. 7 is a cross-sectional side view of the adapter assembly of FIGS. 3-5 taken along line 7-7 in FIG. 6;

FIG. 8 is an enlarged, perspective view of a coupling assembly and a transfer assembly of the adapter assembly of FIGS. 3-7;

FIG. 9 is a perspective side view of the adapter assembly of FIGS. 3-7 with the housing assemblies removed;

FIG. 10 is an enlarged view of the indicated area of detail of FIG. 9;

FIG. 11 is an enlarged view of the indicated area of detail of FIG. 6;

FIG. 12 is an enlarged view of the indicated area of detail of FIG. 7;

FIG. 13 is a perspective end view of the transfer assembly of FIG. 8;

FIG. 14 is an enlarged view of the indicated area of detail of FIG. 6;

FIG. 15 is an enlarged view of the indicated area of detail of FIG. 7;

FIG. 16 is an enlarged view of the indicated area of detail of FIG. 9;

FIG. 17 is a perspective side view of the extension assembly of FIG. 1;

FIG. 18 is a perspective side view of an inner flexible band assembly of the extension assembly of FIG. 17;

FIG. 19 is a perspective side view of an outer flexible band assembly of the extension assembly of FIG. 17;

FIG. 20 is a perspective side view of the inner and outer flexible band assemblies of FIGS. 18 and 19 and an exploded view of a frame assembly of the extension assembly of FIG. 17;

FIG. 21 is a perspective side view of the inner and outer flexible band assemblies and the frame assembly of FIG. 20;

FIG. 22 is an enlarged view of the indicated area of detail of FIG. 21;

FIG. 23 is a front, perspective view of the inner and outer flexible band assemblies and the frame assembly of FIG. 20;

FIG. 24 is an enlarged view of the indicated area of detail of FIG. 23;

FIG. 25 is a cross-sectional end view taken along line 25-25 of FIG. 17;

FIG. 26 is a cross-sectional end view taken along line 26-26 of FIG. 17;

FIG. 27 is an enlarged perspective side view of a distal end of the inner and outer flexible band assemblies and the frame assembly of FIG. 20 including a proximal seal member and first and second distal seal members;

FIG. 28 is an exploded perspective view of the proximal seal member and first and second distal seal members of FIG. 27;

FIG. 29 is an exploded view of a trocar assembly of the extension assembly of FIG. 17;

FIG. 30 is a perspective side view of the trocar assembly of FIG. 29;

FIG. 31 is a cross-sectional side view taken along line 31-31 of FIG. 30;

FIG. 32 is a cross-sectional top view taken along line 32-32 of FIG. 17;

FIG. 33 is an enlarge cross-sectional view of the distal end of the extension assembly of FIG. 17;

FIG. 34 is a perspective side view of the adapter assembly of FIG. 3 connected to the extension assembly of FIG. 17 and an end effector and an anvil assembly connected to the extension assembly;

FIG. 35 is an enlarged cross-sectional side view of the indicated area of detail of FIG. 34;

FIG. 36 is a rear, perspective view of an adapter assembly according to another embodiment of the present disclosure;

FIG. 37 is a perspective side view of the adapter assembly of FIG. 36 with an outer sleeve and a handle member removed;

FIG. 38 is a perspective side view of the adapter assembly of FIG. 37 with a base and a housing member removed;

FIG. 39 is a perspective side view of the adapter assembly of FIG. 38 with a support structure removed;

FIG. 40 is a cross-sectional side view taken along line 40-40 of FIG. 36;

FIG. 41 is a cross-sectional side view taken along line 41-41 of FIG. 40;

FIG. 42 is a rear, perspective view of an adapter assembly according to yet another embodiment of the present disclosure;

FIG. 43 is a cross-sectional side view taken along line 43-43 of FIG. 42;

FIG. 44 is a cross-sectional side view taken along line 44-44 of FIG. 42;

FIG. 45 is a perspective view of a connector assembly according to an embodiment of the present disclosure;

FIG. 46 is an exploded perspective view of the connector assembly of FIG. 45;

FIG. 47 is a perspective view of the connector assembly of FIG. 45 with a sleeve and first section of a tubular extension removed;

FIG. 48 is a perspective view of the connector assembly of FIG. 45 with the sleeve removed;

FIG. 49 is a cross-sectional side view taken along line 49-49 of FIG. 45;

FIG. 50 is a perspective view, with parts separated, of a distal end of the adapter assembly of FIG. 1 in accordance with embodiments of the present disclosure;

FIG. 51 is a transverse cross-sectional view of a portion of the distal end of the adapter assembly of FIG. 50;

FIG. 52 is a longitudinal cross-sectional view of the distal end of the adapter assembly taken along line 52-52 of FIG. 50;

FIGS. 53 and 54 are perspective views of a distal portion of the adapter assembly of FIG. 50, with some parts removed; and

FIG. 55 is a perspective view of a sensor assembly of the adapter assembly of FIG. 50.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed adapter assemblies and extension assemblies for surgical devices and/or handle assemblies are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to that portion of the adapter assembly or surgical device, or component thereof, farther from the user, while the term “proximal” refers to that portion of the adapter assembly or surgical device, or component thereof, closer to the user.

With reference to FIG. 1, an adapter assembly in accordance with an embodiment of the present disclosure, shown generally as adapter assembly 100, and an extension assembly according to an embodiment of the present disclosure, shown generally as extension assembly 200, are configured for selective connection to a powered handheld electromechanical instrument shown, generally as surgical device 10. As illustrated in FIG. 1, surgical device 10 is configured for selective connection with adapter assembly 100, and, in turn, adapter assembly 100 is configured for selective connection with an extension assembly 200. Extension assembly 200 is configured for selective connection with a tool assembly or end effector, e.g. tool assembly 30 (FIG. 34), including a loading unit, e.g. loading unit 40 (FIG. 34), and an anvil assembly, e.g., anvil assembly 50 (FIG. 34), for applying a circular array of staples (not shown) to tissue (not shown).

As illustrated in FIGS. 1 and 2, surgical device 10 includes a handle housing 12 having a lower housing portion 14, an intermediate housing portion 16 extending from and/or supported on lower housing portion 14, and an upper housing portion 18 extending from and/or supported on intermediate housing portion 16. A distal half-section of upper housing portion 18 defines a nose or connecting portion 18 a configured to accept a corresponding drive coupling assembly 110 (FIG. 10) of adapter assembly 100. For a detailed description of the structure and function of an exemplary electromechanical instrument, please refer to commonly owned U.S. Pat. Appl. Publ. No. 2012/0253329 (“the '329 application”), the contents of which is incorporated by reference herein in its entirety.

Adapter assembly 100 will now be described with reference to FIGS. 3-20. Referring initially to FIG. 3, adapter assembly 100 includes a proximal end 102 configured for operable connection to connecting portion 18 a (FIG. 1) of surgical device 10 (FIG. 1) and a distal end 104 configured for operable connection to extension assembly 200 (FIG. 1). In accordance with the present disclosure, adapter assembly 100 may be substantially or fully rigid along the entire length.

Turning to FIGS. 3-5, from proximal end 102 to distal end 104 of adapter assembly 100, adapter assembly 100 includes a drive coupling assembly 110, a drive transfer assembly 130 operably connected to drive coupling assembly 110, a first pusher assembly 160 operably connected to drive transfer assembly 130, and a second pusher assembly 180 operably connected to drive transfer assembly 130. Each of drive transfer assembly 130, first pusher assembly 160 and second pusher assembly 180 are operably maintained within an outer sleeve 106 (FIG. 3). As will be described in further detail below, a shaft 108 (FIG. 3) extends longitudinally through adapter assembly 100 and is operably connected to drive transfer assembly 130.

With reference to FIGS. 5-9, drive coupling assembly 110 has a cylindrical profile and is configured to selectively secure adapter assembly 100 to surgical device 10 (FIG. 1). Drive coupling assembly 110 includes a connector housing 112 and a connector extension 114 fixedly connected to connector housing 112 by a mounting plate 113. Connector housing 112 and connector extension 114 operate to rotatably support a first rotatable proximal drive shaft 116, a second rotatable proximal drive shaft 118, and a third rotatable proximal drive shaft 120. Connector housing 112 and connector extension 114 of drive coupling assembly 110 also rotatably supports first, second, and third connector sleeves 122, 124, and 126, respectively. Each of connector sleeves 122, 124, 126 is configured to mate with respective first, second, and third drive connectors (not shown) of surgical device 10 (FIG. 1). Each connector sleeve 122, 124, 126 is further configured to mate with a proximal end 116 a, 118 a, 120 a of respective first, second and third proximal drive shafts 116, 118, 120.

Drive coupling assembly 110 also includes first, second and third biasing members 122 a, 124 a and 126 a disposed distally of respective first, second and third connector sleeves 122, 124, 126. Each of biasing members 122 a, 124 a and 126 a is disposed about respective first, second, and third rotatable proximal drive shafts 116, 118 and 120 to help maintain connector sleeves 122, 124, and 126 engaged with the distal end of respective drive rotatable drive connectors (not shown) of surgical device 10 when adapter assembly 100 is connect to surgical device 10. In particular, first, second and third biasing members 122 a, 124 a and 126 a function to bias respective connector sleeves 122, 124 and 126 in a proximal direction.

For a detailed description of an exemplary drive coupling assembly, please refer to the '329 application, the contents of which was previously incorporated by reference herein.

With reference to FIGS. 9-13, drive transfer assembly 130 (FIGS. 10 and 13) of adapter assembly 100 has a cylindrical profile and operably connects distal ends of first, second and third rotatable proximal drive shafts 116, 118 and 120 to shaft 108, first pusher assembly 160, and second pusher assembly 180, respectively. Drive transfer assembly 130 includes a support plate 132 (FIGS. 11 and 12) secured to a proximal end of connector housing 112 and a drive transfer housing 134 positioned adjacent support plate 132. Support plate 132 and housing 134 operate to rotatably support a first rotatable distal drive shaft 136, a second rotatable distal drive shaft 138 and a drive member 140.

First and second rotatable distal drive shafts 136 and 138 are each operably connected to respective first and second rotatable proximal drive shafts 116 and 118 of drive coupling assembly 110 by a pair of gears. In particular, distal ends of each of first and second rotatable proximal drive shaft 116 and 118 include a geared portion 142 a and 144 a, respectively, which engages a proximal drive gear 142 b and 144 b on a proximal end of respective first and second distal drive shafts 136 and 138. As shown, each of respective paired geared portion and proximal drive gear 142 a, 142 b and 144 a, 144 b are the same size to provide a 1:1 gear ratio between the respective rotatable proximal and distal drive shafts. In this manner, respective rotatable proximal and distal drive shafts rotate at the same speed. However, it is envisioned that either or both of the paired geared portions and proximal drive gears may be of different sizes to alter the gear ratio between the rotatable proximal and distal drive shafts.

A distal end of third proximal drive shaft 120 of drive coupling assembly 110 includes a geared portion 146 a that engages a geared portion 146 b formed on a proximal end of drive member 140 of drive transfer assembly 130. The size of geared portion 146 a on third proximal drive shaft 120 and geared portion 146 b on drive member 140 are the same size to provide a 1:1 gear ratio between third proximal drive shaft 120 and drive member 140. In this manner, third proximal drive shaft 120 and drive member 140 rotate at the same speed. However, it is envisioned that either or both of geared portions 146 a, 146 b may be of different sizes to alter the gear ratio between third proximal drive shaft 120 and drive member 140. A distal end of drive member 140 defines a socket 145 that receives a proximal end 108 a of shaft 108. Alternatively, socket 145 may be configured to operably engage a proximal end 208 a of a drive shaft (FIG. 17) of an extension assembly 200 (FIG. 17).

Drive transfer assembly 130 also includes a drive connector 148 (FIG. 11) operably connecting first rotatable distal drive shaft 136 to first pusher assembly 160 and a tubular connector 150 operably connecting second rotatable distal drive shaft 138 to second pusher assembly 180. In particular, a distal end of first rotatable distal drive shaft 136 includes a geared portion 152 a that engages a geared portion 152 b of drive connector 148. A distal end of second rotatable distal drive shaft 138 includes a geared portion 154 a that engages a drive gear 154 b secured to a proximal end of tubular connector 150.

As shown in FIG. 10, geared portion 152 a of first rotatable distal drive shaft 136 is smaller than geared portion 152 b of drive connector 148 to provide a gear ratio of greater than 1:1 between first rotatable distal drive shaft 136 and drive connector 148. In this manner, drive connector 148 rotates at a slower speed than first rotatable distal drive shaft 136. Similarly, geared portion 154 a of second rotatable distal drive shaft 138 is smaller than drive gear 154 b on tubular connector 150 to provide a gear ratio of greater than 1:1 between second rotatable distal drive shaft 138 and drive connector 148. In this manner, tubular connector 150 rotates at a slower speed than second rotatable distal drive shaft 138. However, it is envisioned that each of paired geared portion 152 a and geared portion 152 b, and geared portion 154 a and drive gear 154 b may be the same size to provide a gear ratio of 1:1 between respective first rotatable distal drive shaft 136 and drive connector 148 and between second rotatable distal drive shaft 138 and tubular connector 150.

With particular reference to FIGS. 9-13, first pusher assembly 160 includes proximal and distal housing sections 162, 164 (FIG. 11), a planetary gear assembly 166 operably mounted within proximal housing section 162, a screw member 168 (FIG. 11) operably connected to planetary gear assembly 166 and rotatably supported within distal housing section 164, and a pusher member 170 (FIG. 11) operably connected to screw member 168 and slidably disposed within distal housing section 164. Planetary gear assembly 166 includes first and second planetary gear systems 166 a, 166 b (FIG. 10). First planetary gear system 166 a includes a central drive gear 172 a mounted on a distal end of drive connector 148 of drive transfer assembly 130 and a plurality of planetary gears 174 a rotatably mounted to a rotatable support ring 176.

Each planetary gear 174 a of first planetary gear system 166 a engages central drive gear 172 a and a toothed inner surface 165 of proximal housing section 162. As central drive gear 172 a rotates in a first direction, i.e., clockwise, each planetary gear 174 a rotates in a second direction, i.e., counter-clockwise. As each planetary gear 174 a rotates in the second direction, engagement of planetary gears 174 a with toothed inner surface 165 of proximal housing section 162 causes rotatable support ring 176 to rotate in the first direction. Conversely, rotation of central drive gear 172 a in the second direction causes rotation of each planetary gear 174 a in the first direction thereby causing rotation of rotatable support ring 176 in the second direction. The configuration of first planetary gear system 166 a provides a reduction in the gear ratio. In this manner, the speed of rotation of rotatable support ring 176 is less than the speed of rotation of central drive gear 172 a.

Second planetary gear system 166 b includes a central drive gear 172 b securely affixed to rotatable support ring 176 and a plurality of planetary gears 174 b rotatably mounted to a proximal end surface 168 a of screw member 168. Each planetary gear 174 b of second planetary gear system 166 b engages central drive gear 172 b and toothed inner surface 165 of proximal housing section 162. As rotatable support ring 176 of first planetary gear system 166 a rotates in the first direction thereby causing central drive gear 172 b to also rotate in the first direction, each planetary gear 174 b rotates in the second direction. As each planetary gear 174 b rotates in the second direction, engagement of planetary gears 174 b with toothed inner surface 165 of proximal housing section 162 causes screw member 168 to rotate in the first direction. Conversely, rotation of central drive gear 172 b in the second direction causes rotation of each planetary gear 174 b in the first direction, thereby causing screw member 168 to rotate in the second direction. The configuration of second planetary gear system 166 b provides a reduction in the gear ratio. In this manner, the speed of rotation of screw member 168 is less than the speed of rotation of central drive gear 172 b. First and second planetary gear systems 166 a, 166 b operate in unison to provide a reduction in the gear ratio between first rotatable proximal drive shaft 116 and screw member 168. In this manner, the reduction in the speed of rotation of screw member 168 relative to drive connector 148 is a product of the reduction provided by the first and second planetary gear systems 166 a, 166 b.

Screw member 168 is rotatably supported within proximal housing portion 162 and includes a threaded distal end 168 b that operably engages a threaded inner surface 170 a of pusher member 170. As screw member 168 is rotated in the first direction, engagement of threaded distal end 168 b of screw member 168 with threaded inner surface 170 a of pusher member 170 (which is keyed to permit axial translation and prevent rotation thereof) causes longitudinal advancement of pusher member 170, as indicated by arrows “A” in FIG. 12. Conversely, rotation of screw member 168 in the second direction causes retraction of pusher member 170.

Pusher member 170 of first pusher assembly 160 of adapter assembly 100 includes a pair of tabs 178 formed on a distal end thereof for engaging connector extensions 240, 242 (FIG. 19) of outer flexible band assembly 230 (FIG. 19) of extension assembly 200 (FIG. 17). Although shown as tabs 178, it is envisioned that pusher member 170 may include any structure suitable for selectively engaging connector extensions 240, 242 of outer flexible band 230 of extension assembly 200.

With particular reference now to FIGS. 14-16, second pusher assembly 180 is substantially similar to first pusher assembly 160, and includes proximal and distal housing sections 182, 184, a planetary gear assembly 186 operably mounted within proximal housing section 182, a screw member 188 operably connected to planetary gear assembly 186 and rotatably supported within distal housing section 184, and a pusher member 190 operably connected to screw member 188 and slidably disposed within distal housing section 184. Planetary gear assembly 186 includes first and second planetary gear systems 186 a, 186 b (FIG. 16). First planetary gear system 186 a includes a central drive gear 192 a mounted on a distal end of tubular connector 150 of drive transfer assembly 130 and a plurality of planetary gears 194 a rotatably mounted to a rotatable support ring 196.

Each planetary gear 194 a of first planetary gear system 186 a engages central drive gear 192 a and a toothed inner surface 185 of proximal housing section 182. As central drive gear 192 a rotates in a first direction, i.e., clockwise, each planetary gear 194 a rotates in a second direction, i.e., counter-clockwise. As each planetary gear 194 a rotates in the second direction, engagement of planetary gears 194 a with toothed inner surface 185 of distal housing section 182 causes rotatable support ring 196 to rotate in the first direction. Conversely, rotation of central drive gear 192 a in the second direction causes rotation of each planetary gear 194 a in the first direction thereby causing rotation of rotatable support ring 196 in the second direction. The configuration of first planetary gear system 186 a provides a reduction in the gear ratio. In this manner, the speed of rotation of rotatable support ring 196 is less than the speed of rotation of central drive gear 192 a.

Second planetary gear system 186 b includes a central drive gear 192 b securely affixed to rotatable support ring 196 and a plurality of planetary gears 194 b rotatably mounted to a proximal end surface 188 a of screw member 188. Each planetary gear 194 b of second planetary gear system 186 b engages central drive gear 192 b and toothed inner surface 185 of proximal housing section 182. As rotatable support ring 196 of first planetary gear system 186 a rotates in the first direction thereby causing central drive gear 192 b to also rotate in the first direction, each planetary gear 194 b rotates in the second direction. As each planetary gear 194 b rotates in the second direction, engagement of planetary gears 194 b with toothed inner surface 185 of proximal housing section 182 causes screw member 188 to rotate in the first direction. Conversely, rotation of central drive gear 192 b in the second direction causes rotation of each planetary gear 194 b in the first direction, thereby causing screw member 188 to rotate in the second direction. The configuration of second planetary gear system 186 b provides a reduction in the gear ratio. In this manner, the speed of rotation of screw member 188 is less than the speed of rotation of central drive gear 192 b. First and second planetary gear systems 186 a, 186 b operate in unison to provide a reduction in the gear ratio between second rotatable proximal drive shaft 118 and screw member 188. In this manner, the reduction in the speed of rotation of screw member 188 relative to tubular connector 150 is a product of the reduction provided by the first and second planetary gear systems 186 a, 186 b.

Screw member 188 is rotatably supported within proximal housing portion 182 and includes a threaded distal end 188 b that operably engages a threaded inner surface 190 a of pusher member 190. As screw member 188 is rotated in the first direction, engagement of threaded distal end 188 b of screw member 188 with threaded inner surface 190 a of pusher member 190 (which is keyed to permit axial translation and prevent rotation thereof) causes longitudinal advancement of pusher member 190. Conversely, rotation of screw member 188 in the second direction causes retraction of pusher member 190.

Pusher member 190 of second pusher assembly 180 of adapter assembly 100 includes a pair of tabs 198 formed on a distal end thereof for engaging connector extensions 220, 222 (FIG. 18) of inner flexible band assembly 210 (FIG. 18) of extension assembly 200 (FIG. 17). Although shown as tabs 198, it is envisioned that pusher member 190 may include any structure suitable for selectively engaging connector extensions 240, 242 of outer flexible band 230 of extension assembly 200.

Turning now to FIGS. 17-34, extension assembly 200 for operably connecting adapter assembly 100 (FIG. 3) with a circular loading unit, e.g. loading unit 40 (FIG. 34) and an anvil assembly, e.g., anvil assembly 50 (FIG. 34) will be described. In particular, a proximal end 202 of extension assembly 200 operably connects with distal end 104 (FIG. 3) of adapter assembly 100 (FIG. 3) and a distal end 204 of extension assembly 200 operably connects with loading unit 40 and anvil assembly 50. As shown, extension assembly 200 provides a slight curvature between proximal and distal end 202, 204. In an alternative embodiment, extension assembly 200 may be straight or may include a greater curvature. In accordance with the present disclosure, extension assembly 200 may be substantially or fully rigid along its entire length.

Although extension assembly 200 will be shown and described as being used to connect loading unit 40 and anvil assembly 50 to adapter assembly 100 (FIG. 3), it is envisioned that the aspects of the present disclosure may be modified for use with various loading units, anvil assemblies, and adapter assemblies. Exemplary loading units and anvil assemblies are described in commonly owned U.S. Pat. No. 8,590,763, and U.S. patent application Ser. Nos. 14/056,301 and 14/149,355, the contents of each being incorporated herein by reference in their entirety.

Extension assembly 200 includes an inner flexible band assembly 210 (FIG. 18), an outer flexible band assembly 230 (FIG. 19) slidably disposed about inner flexible band assembly 210, a frame assembly 250 (FIG. 20) for supporting inner and outer flexible band assemblies 210, 230, a trocar assembly 270 (FIG. 28) operably received through inner and outer flexible band assemblies 210, 230, and a connector assembly 290 for securing loading unit 40 (FIG. 34) to extension assembly 200. An outer sleeve 206 (FIG. 17) is received about frame assembly 250 and trocar assembly 270, and inner and outer flexible band assemblies 210, 230 are slidably received through outer sleeve 206. As will be described in further detail below, extension assembly 200 may include a drive shaft 208 operably connected to trocar assembly 270 and extending through proximal end 202 of extension assembly 200.

With reference to FIG. 18, inner flexible band assembly 210 includes first and second inner flexible bands 212, 214, a support ring 216, a support base 218, and first and second connection extensions 220, 222. Proximal ends 212 a, 214 a of respective first and second inner flexible bands 212, 214 are laterally spaced apart and securely attached to support ring 216. Distal ends 212 b, 214 b of first and second inner flexible bands 212, 214 are laterally spaced apart and securely attached to a proximal end 218 a of support base 218. Each of first and second inner flexible bands 212, 214 may be attached to support ring 216 and/or support base 218 in any suitable manner, including, for example, by press-fitting, welding, adhesives, and/or with mechanical fasteners. As will be described in further detail below, inner flexible band assembly 210 is configured to be slidably received about trocar assembly 270 (FIG. 28) and within outer flexible band assembly 230 (FIG. 19) and outer sleeve 206 (FIG. 17).

First and second connection extensions 220, 222 of inner flexible band assembly 210 extend proximally from support ring 216 and operably connect inner flexible band assembly 210 with pusher member 190 (FIG. 15) of second pusher assembly 180 (FIG. 15) of adapter assembly 100 (FIG. 3). In particular, each of first and second connection extensions 220, 222 define respective openings 221, 223 configured to receive tabs 198 (FIG. 15) of pusher member 190 (FIG. 15) of second pusher assembly 180. Receipt of tabs 198 of pusher member 190 within openings 221, 223 of respective first and second extensions 220, 222 secure inner flexible band assembly 210 of extension assembly 200 with second pusher assembly 180 of adapter assembly 100. First and second connection extensions 220, 222 may be integrally formed with support ring 216, or attached thereto in any suitable manner.

Support base 218 extends distally from inner flexible bands 212, 214 and is configured to selectively connect extension assembly 200 with loading unit 40 (FIG. 34). Specifically, a distal end 218 b of support base 218 includes a flange 224 for operable engagement with an axially movable assembly (not shown) of loading unit 40 (FIG. 34). In one embodiment, flange 224 is configured for connection with a knife assembly (not shown) of loading unit 40 (FIG. 34).

With reference now to FIG. 19, outer flexible band assembly 230 is substantially similar to inner flexible band assembly 210 and includes first and second flexible bands 232, 234 laterally spaced and connected on proximal ends 232 a, 234 a to a support ring 236 and on distal ends 234 b, 234 b to a proximal end 238 a of a support base 238. Each of first and second outer flexible bands 232, 234 may be attached to support ring 236 and support base 238 in any suitable manner, including, for example, by press-fitting, welding, adhesives, and/or with mechanical fasteners. As will be described in further detail below, outer flexible band assembly 230 is configured to receive trocar assembly 270 (FIG. 28) therethrough.

First and second connection extensions 240, 242 of outer flexible band assembly 230 extend proximally from support ring 236 and operably connect outer flexible band assembly 230 with pusher member 170 (FIG. 12) of first pusher assembly 160 (FIG. 12) of adapter assembly 100 (FIG. 1). In particular, each of first and second connection extensions 240, 242 define respective openings 241, 243 configured to receive tabs 178 (FIG. 12) of pusher member 170 of first pusher assembly 160. Receipt of tabs 178 of pusher member 170 within openings 241, 243 of respective first and second extensions 240, 242 secures outer flexible band assembly 230 of extension assembly 200 with first pusher assembly 160 of adapter assembly 100. First and second connection extensions 240, 242 may be integrally formed with support ring 236, or attached thereto in any suitable manner.

Support base 238 extends distally from outer flexible bands 232, 234 and is configured to selectively connect extension assembly 200 with loading unit 40 (FIG. 34). Specifically, a distal end 238 b of support base 238 includes a flange 244 for operable engagement with an axially movable assembly (not shown) of a loading unit (not shown). In one embodiment, flange 244 is configured for connection with a staple pusher assembly (not shown) of loading unit 40 (FIG. 34).

With reference now to FIGS. 20-26, frame assembly 250 includes first and second proximal spacer members 252, 254, and first and second distal spacer members 256, 258. When secured together, first and second proximal spacer members 252, 254 define a pair of inner longitudinal slots 253 a for slidably receiving first and second flexible bands 212, 214 (FIG. 18) of inner flexible band assembly 210 (FIG. 18) and a pair of outer longitudinal slots 253 b for slidably receiving first and second flexible bands 232, 234 (FIG. 19) of outer flexible band assembly 230 (FIG. 19). First and second proximal spacer members 252, 254 further define a longitudinal passage 255 for receipt of trocar assembly 270.

In one embodiment, and as shown, first and second proximal spacer members 252, 254 are formed of plastic and are secured together with a snap-fit arrangement. Alternatively, first and second proximal spacer members 252, 254 may be formed of metal or other suitable material and may be secured together in any suitable manner, including by welding, adhesives, and/or using mechanical fasteners.

First and second distal spacer members 256, 258 define a pair of inner slots 257 a for slidably receiving first and second flexible bands 212, 214 (FIG. 18) of inner flexible band assembly 210 (FIG. 18) and a pair of outer slots 257 b for slidably receiving first and second flexible bands 232, 234 (FIG. 19) of outer flexible band assembly 230 (FIG. 19). First and second distal spacer members 256, 258 further define a longitudinal passage 259 for receipt of trocar assembly 270.

In one embodiment, and as shown, each of first and second distal spacer members 256, 258 are secured about inner and outer flexible band assemblies 210, 230 and to outer sleeve 206 (FIG. 17) by a pair of screws 260 a, 260 b (FIG. 26). Alternatively, first and second distal spacer members 256, 258 may be secured together in any suitable manner, including by welding, adhesives, and/or using mechanical fasteners. First and second distal spacer members 256, 258 may be formed of metal or any other suitable material.

With reference now to FIGS. 27 and 28, frame assembly 250 further includes a proximal seal member 262 and first and second distal seal members 264, 266. Each of proximal seal member 252 and first and second distal seal members 264, 266 include seals halves 262 a, 262 b, 264 a, 264 b, 266 a, 266 b, respectively. Proximal seal member 262 is received between first and second proximal spacer members 252, 254 and first and second distal spacer members 256, 258. First half 264 a of first distal seal member 264 is secured to first half 266 a of second distal seal member 266 and second half 264 b of first distal seal member 264 is secured to second half of second distal seal member 266. Proximal seal member 262 and first and second distal seal members 264, 266 engage outer sleeve 206 (FIG. 17), inner and outer flexible bands 212, 214 and 232, 234 of respective inner and outer flexible band assemblies 210, 230 and trocar assembly 270 (FIG. 28) in a sealing manner. In this manner, proximal seal member 262 and first and second distal seal members 264, 266 operate to provide a fluid tight seal between distal end 204 and proximal end 202 of extension assembly 200.

With reference to FIGS. 29-32, trocar assembly 270 of extension assembly 200 includes an outer housing 272, a trocar member 274 slidably disposed within tubular outer housing 272, and a drive screw 276 operably received within trocar member 274 for axially moving trocar member 274 relative to tubular housing 272. In particular, trocar member 274 includes a proximal end 274 a having an inner threaded portion 275 which engages a threaded distal portion 276 b of drive screw 276. As drive screw 276 is rotated within trocar member 274, engagement of inner threaded portion 275 of trocar member 274 with threaded distal portion 276 b of drive screw 276 causes longitudinal movement of trocar member 274 within outer housing 272 of trocar assembly 270. Rotation of drive screw 276 in a first direction causes longitudinal advancement of trocar member 274 and rotation of drive screw 276 in a second direction causes longitudinal retraction of trocar member 274. A distal end 274 b of trocar member 274 is configured to selectively engage anvil assembly 50 (FIG. 34).

A bearing assembly 278 is mounted to a proximal end 272 a of outer housing 272 of trocar assembly 270 for rotatably supporting a proximal end 276 a of drive screw 276 relative to outer housing 272 and trocar member 274. Bearing assembly 278 includes a housing 280, proximal and distal spacers 282 a, 282 b, proximal and distal retention clips 284 a, 284 b, proximal and distal bearings 286 a, 286 b, and a washer 288. As shown, proximal end 276 a of drive screw 276 includes a flange 276 c for connection with a link assembly 277. A distal portion 277 b of link assembly 277 is pivotally received between first and second proximal spacer members 252, 254 and operably engages flange 276 c on drive screw 276. A proximal end 277 a of link assembly 277 is configured for operable engagement with a distal end 208 b of drive shaft 208.

With reference now to FIGS. 32 and 33, connector assembly 290 of extension assembly 200 includes a tubular connector 292 attached to a distal end 206 a of outer sleeve 206 and about distal ends of inner and outer flexible assemblies 210, 230 (FIG. 26) and trocar assembly 270. In particular, a proximal end 292 a of tubular connector 292 is received within and securely attached to distal end 206 b of outer sleeve 206 by a retaining clip 294. An O-ring 296 forms a fluid tight seal between tubular connector 292 of connector assembly 290 and outer sleeve 206. A distal end 292 b of tubular connector 292 is configured to selectively engage a proximal end of loading unit 40 (FIG. 34). Distal end 292 b of tubular connector 292 engages the circular loading unit with a snap-fit arrangement, bayonet coupling, or in another suitable manner.

With reference now to FIGS. 34 and 35, extension assembly 200 is connected to adapter assembly 100 by receiving proximal end 202 (FIG. 17) of extension assembly 200 within distal end 104 of adapter assembly 100. In particular, first and second connection extensions 220, 240, 222, 242 of respective inner and outer flexible band assemblies 210, 230 are received within sleeve 106 of adapter assembly 100 such that tabs 178 of pusher member 170 of first pusher assembly 160 of adapter assembly 100 are received within openings 241, 243 of respective first and second connection extensions 240, 242 of outer flexible band assembly 230 to secure outer flexible band assembly 230 with first pusher assembly 160 and tabs 198 of pusher member 190 of second pusher assembly 180 of adapter assembly 100 are received within openings 221, 223 of first and second connection extensions 221, 223 of inner flexible band assembly 210 to secure inner flexible band assembly 210 with second pusher assembly 180.

As noted above, adapter assembly 100 may include a drive shaft 108 (FIG. 3) that extends from distal end 104 of adapter assembly 100. Alternatively, extension assembly 200 may include a drive shaft 208 extending from proximal portion 202 of extension assembly 200. In the event both adapter assembly 100 includes drive shaft 108 and extension assembly 200 includes drive shaft 208, prior to receipt of proximal portion 202 of extension assembly 200 within distal end 104 of extension assembly 100, one of drive shaft 108, 208 must be removed from respective adapter assembly 100 and extension assembly 200. During receipt of proximal portion 202 of extension assembly 200 within distal end 102 of adapter assembly 100, either distal end 108 b (FIG. 35) of drive shaft 108 (FIG. 35) engages proximal portion 277 b (FIG. 35) of link assembly 277, or proximal end 208 a (FIG. 17) of drive shaft 208 (FIG. 17) is received within socket 145 of drive member 140 of drive transfer assembly 130 of extension assembly 100 (FIG. 12).

After extension assembly 200 is operably engaged with adapter assembly 100, and adapter assembly 100 is operably engaged with surgical device 10 (FIG. 1), loading unit 40 (FIG. 34) of end effector 30 (FIG. 34) may be attached to connector assembly 290 of extension assembly 200 and an anvil assembly 50 (FIG. 34) may be attached to distal end 274 b of trocar 274 of extension assembly 200 in a conventional manner. During actuation of loading unit 40 and anvil assembly 50, longitudinal advancement of pusher member 190 of second pusher assembly 180 of adapter assembly 100, as described above, and as indicated by arrows “C” in FIG. 35, causes longitudinal advancement of outer flexible band assembly 230 of extension assembly 200 and longitudinal advancement of pusher member 170 of first pusher assembly 160, as described above, and as indicated by arrows “D” in FIG. 35, causes longitudinal advancement of inner flexible band assembly 210. Rotation of drive shaft 108 in a first direction, as described above, and as indicated by arrow “E”, causes advancement of trocar 274 of extension assembly 200. Conversely, longitudinal retraction of pusher member 190 causes longitudinal retraction of outer flexible band assembly 230, longitudinal retraction of pusher member 170 causes longitudinal retraction of inner flexible band assembly 210, and rotation of drive shaft 108 in a second direction causes retraction of trocar 274 of extension assembly 200.

In one embodiment, inner flexible band assembly 210 is operably connected to a knife assembly (not show) of loading unit 40 (FIG. 34) of end effector 30 (FIG. 34) attached to connector assembly 290 of extension assembly 200, outer flexible band assembly 230 is operably connected to a staple driver assembly (not shown) of loading unit 40, and trocar 274 is operably connected to anvil assembly 50 (FIG. 34) of end effector 30 (FIG. 34). In this manner, longitudinal movement of inner flexible band assembly 210 causes longitudinal movement of the knife assembly, longitudinal movement of outer flexible band assembly 230 causes longitudinal movement of the staple driver assembly, and longitudinal movement of trocar 274 causes longitudinal movement of anvil assembly 50 relative to loading unit 40.

With reference to FIGS. 36-41, an adapter assembly according to another embodiment of the present disclosure is shown as adapter assembly 300. Adapter assembly 300 is substantially similar to adapter assembly 100 described hereinabove and will only be described as it relates to the differences therebetween.

As will become apparent from the following description, the configuration of adapter assembly 300 permits rotation of a distal portion 304 of adapter assembly 300 about a longitudinal axis “X” (FIG. 37), relative to a proximal portion 302 of adapter assembly 300. In this manner, an end effector, e.g. end effector 30 (FIG. 34) secured to distal portion 304 of adapter assembly 300 or an end effector secured to an extension assembly, e.g., extension assembly 200 (FIG. 17) which is secured to distal portion 304 of adapter assembly 300 is rotatable about longitudinal axis “X” independent of movement of the surgical device (not shown) to which adapter assembly 300 is attached.

Adapter assembly 300 includes a base 306 and a support structure 308 rotatable relative to base 306 along longitudinal axis “X” of adapter assembly 300. A rotation handle 310 is rotatably secured to base 306 and fixedly secured to a proximal end of support structure 308. Rotation handle 310 permits longitudinal rotation of distal portion 304 of adapter assembly 300 relative to proximal end 302 of adapter assembly 300. As will be described in further detail below, a latch 312 is mounted to rotation handle 310 and selectively secures rotation handle 310 in a fixed longitudinal position.

Proximal portion 302 of adapter assembly 300 includes a drive coupling assembly 320 and a drive transfer assembly 330 operably connected to drive coupling assembly 320. Distal portion 304 of adapter assembly 300 includes a first pusher assembly 340 operably connected to drive transfer assembly 330, and a second pusher assembly 350 operably connected to drive transfer assembly 330. Drive coupling assembly 320 and drive transfer assembly 330 are mounted within base 306, and thus, remain rotationally fixed relative to the surgical device (not shown) to which adapter assembly 300 is attached. First pusher assembly 340 and second pusher assembly 350 are mounted within support structure 308, and thus, are rotatable relative to the surgical device (not shown) to which adapter assembly 300 is attached.

Drive coupling assembly 320 is configured to selectively secure adapter assembly 300 to a surgical device (not shown). For a detailed description of an exemplary surgical device and drive coupling assembly, please refer to commonly owned U.S. Provisional Patent Application Ser. No. 61/913,572, filed Dec. 9, 2013, the content of which is incorporated by reference herein in its entirety.

Rotation knob 310 is rotatably secured to base 306. Latch 312 includes a pin 312 a (FIG. 40) configured to lock rotation knob 310 relative to base 306. In particular, pin 312 a of latch 312 is received within a slot 307 formed in base 306 and is biased distally by a spring 314 into a notch 307 a (FIG. 40) formed in base 306 and in communication with slot 307 to lock rotation knob 310 relative to base 306. Proximal movement of latch 312, as indicated by arrow “F” in FIG. 36, retracts pin 312 a from within notch 307 a to permit rotation of rotation knob 310 relative to base 306. Although not shown, it is envisioned that base 306 may define a number of notches radially spaced about base 306 and in communication with slot 307 that permit rotation knob 310 to be locked in a number of longitudinal orientations relative to base 306.

Drive transfer assembly 330, first drive pusher assembly 340, and second drive pusher assembly 350 of adapter assembly 300 are substantially identical to respective drive transfer assembly 130, first drive pusher assembly 160, and second drive pusher assembly 180 of adapter assembly 100 described hereinabove, and therefore, will only be described as relates to the differences therebetween.

Support structure 308 is fixedly received about first and second drive pusher assemblies 340, 350 and rotatably relative to base 306. As noted above, rotation knob 310 is fixedly secured to the proximal end of support structure 308 to facilitate rotation of support structure 308 relative to base 306. Support structure 308 is retained with outer sleeve 305 of adapter assembly 300 and is configured to maintain axial alignment of first and second drive pusher assemblies 340, 350. Support structure 308 may also reduce the cost of adapter assembly 300 when compared to the cost of adapter assembly 100.

Support structure 308 respectively includes first, second, third, fourth, fifth, sixth, and seventh plates 360 a, 360 b, 360 c, 360 d, 360 e, 360 f, 360 g, a first and a second plurality of tubular supports 362 a, 362 b, first and second support rings 364 a, 364 b, a first and a second plurality of ribs 366 a, 366 b, and a plurality of rivets 368. From proximal to distal, first and second plates 360 a, 360 b are maintained in spaced apart relation to each other by the first plurality of tubular supports 362 a, second and third plates 360 b, 360 c are maintained in spaced apart relation to each other by first support ring 364 a, third and fourth plates 360 c, 360 d are maintained in spaced apart relation to each other by the first plurality of support ribs 366 a, fourth and fifth plates 360 d, 360 e are maintained in spaced apart relation to each other by the second plurality of tubular supports 362 b, fifth and sixth plates 360 e, 360 f are maintained in spaced apart relation to each other by second support ring 364 b, and sixth and seventh plates 360 f, 360 g are maintained in spaced apart relation to each other by the second plurality of support ribs 366 b. First, second, third, fourth, fifth, sixth, and seventh plates 360 a-g are held together by a plurality of rivets 368 secured to first and seventh plates 360 a, 360 g and extending through second, third, fourth, fifth, and sixth plates 360 b-360 f, first and second support rings 364 a, 364 b, and respective first and second plurality of tubular support 362 a, 362 b.

Adapter assembly 300 operates in a substantially similar manner to adapter assembly 100 described hereinabove. In addition, as described in detail above, adapter assembly 300 is configured to permit rotation of an end effector, e.g., end effector 30 (FIG. 34) attached to adapter assembly 300 or attached to an extension assembly that is attached to adapter assembly 300 to be selectively rotated about longitudinal axis “X” (FIG. 37) during use.

With reference now to FIGS. 42-44, an adapter assembly according to another embodiment of the present disclosure is shown generally as adapter assembly 400. Adapter assembly 400 is substantially similar to adapter assemblies 100 and 300 described hereinabove, and therefore will only be described as relates to the differences therebetween.

Adapter assembly 400 includes a proximal portion 402 and a distal portion 404 rotatable along a longitudinal axis “X” relative to proximal portion 402. Distal portion 404 includes a support structure 408 secured to outer sleeve 405 and formed about first and second pusher assemblies 440, 450. Support structure 408 includes a plurality of reinforcing members 462 extending substantially the length of outer sleeve 405. Reinforcing members 462 each include a proximal tab 462 a and a distal tab 462 b which extend through outer sleeve 405 to secure reinforcing member 462 within outer sleeve 405. Proximal tabs 462 of reinforcing members 462 are further configured to engage a rotation knob 410 of adapter assembly 400. Adapter assembly 400 may include annular plates (not shown) positioned radially inward of reinforcing members 462 that maintain proximal and distal tabs 462 a, 462 b of reinforcing members 462 in engagement with outer sleeve 405. The annular plates may also provide structure support to distal portion 404 of adapter assembly 400.

With reference to FIGS. 45-49, a connection assembly according to an embodiment of the present disclosure is shown generally as connection assembly 500. As shown and will be described, connection assembly 500 is configured to be attached to first and second tubular bodies (not shown) for connecting the first tubular body, i.e., adapter assembly 100 (FIG. 3), 300 (FIG. 36), 400 (FIG. 42), to the second tubular body, i.e., extension assembly 200 (FIG. 17). It is envisioned, however, that the aspects of the present disclosure may be incorporated directly into the first and second tubular bodies to permit connection of the first tubular body directly to the second tubular body.

Connection assembly 500 includes a tubular base 510 and a tubular extension 520 formed of first and second sections 520 a, 520 b and an outer sleeve 522. As shown, tubular base 510 defines a pair of openings 511 for securing tubular base 510 to a first tubular body (not shown). Alternatively, tubular base 510 may include only a single opening, one or more tabs (not shown), and/or one or more slots (not shown), for securing tubular base 510 to the first tubular body (not shown). A flange 512 extends from a first end of tubular base 510 and includes an annular rim 514 extending thereabout.

First and second sections 520 a, 520 b of tubular extension 520 are substantially similar to one another and each define an annular groove 521 formed along an inner first surface thereof. Each of first and second section 520 a, 520 b of tubular extension 520 is configured to be received about flange 512 of tubular base 510 such that rim 514 of tubular base 510 is received within grooves 521 of first and second sections 520 a, 520 b of tubular extension 520. Once first and second sections 520 a, 520 b of tubular extension 520 are received about flange 512 of tubular base 510, outer sleeve 522 of tubular extension 520 is received about first and second sections 520 a, 520 b of tubular extension 520 to secure tubular extension 520 to tubular base 510.

As shown, each of first and second sections 520 a, 520 b of tubular extension 520 define an opening 523 configured to be aligned with a pair of openings 525 in outer sleeve 522 to secure outer sleeve 522 to first and second sections 520 a, 520 b. Either or both of first and second sections 520 a, 520 b and outer sleeve 522 may include one or more tabs, and/or one or more slots for securing outer sleeve 522 about first and second extensions. Alternatively, outer sleeve 522 may be secured to first and second sections 520 a, 520 b in any suitable manner.

Outer sleeve 522 may be selectively secured about first and second extensions for selective removal of outer sleeve 522 from about first and second sections 520 a, 520 b to permit separation of tubular extension 520 from tubular base 510. Alternatively, outer sleeve 522 may be permanently secured about first and second sections 520 a, 520 b to prevent tubular extension 520 from being separated from tubular base 510. As noted above, although tubular base 510 and tubular extension 520 are shown and described as forming an independent connection assembly 500, it is envisioned that tubular base 510 may be formed on a first tubular member, i.e., adapter assembly 100 (FIG. 3) and tubular extension 520 may be formed on a second tubular member, i.e., extension assembly 200 (FIG. 17) such that the first tubular member may be directly connected to the second tubular member.

With reference to FIGS. 50-52, an alternate embodiment of a trocar assembly 1270 is shown in combination with an alternate embodiment of an extension assembly 1200. Trocar assembly 1270 is similar to trocar assembly 270 described above, and not all similarities will be discussed herein. However, while trocar assembly 270 is configured for secure engagement to link assembly 277 of extension assembly 200, trocar assembly 1270 is configured for releasable engagement with extension assembly 1200.

With particular reference to FIG. 50, trocar assembly 1270 includes a pair of flattened portions 1280 about its perimeter, and extension assembly 1200 includes a pair of openings 1210 a, 1210 b through its outer wall or sleeve 1206 (opening 1210 a is not visible in FIG. 50). When trocar assembly 1270 is engaged with extension assembly 1200, flattened portions 1280 of trocar assembly 1270 are axially aligned with openings 1210 a, 1210 b of extension assembly 1200. In this position, a pair of retention members 1300 a, 1300 b is insertable through respective openings 1210 a, 1210 b and adjacent (e.g., in contact with) flattened portions 1280.

More particularly, each retention member 1300 a, 1300 b includes an extension portion 1310 a, 1310 b and a receptacle 1320 a, 1320 b, respectively. Each extension portion 1310 a, 1310 b is configured to releasably engage receptacle 1320 a, 1320 b of the opposite retention member 1300 a, 1300 b. That is, extension portion 1310 a of retention member 1300 a is configured to releasably engage receptacle 1320 b of retention member 1300 b; extension portion 1310 b of retention member 1300 b is configured to releasably engage receptacle 1320 a of retention member 1300 a. It is envisioned that extension portions 1310 a, 1310 b respectively engage receptacles 1320 b, 1320 a via a snap-fit connection. It is further envisioned that retention member 1300 a is identical to retention member 1300 b, which may be helpful to minimize manufacturing costs and to facilitate assembly.

In use, to engage trocar assembly 1270 with extension assembly 1200, trocar assembly 1270 is inserted through a distal opening 1202 of extension assembly 1200 until a proximal end 1276 a of a drive screw 1276 of trocar assembly 1200 engages a link assembly of trocar assembly 1200 (see link assembly 277 of trocar assembly 270 in FIG. 32, for example). Next, extension portion 1310 a, 1310 b of each retention member 1300 a, 1300 b, respectively, is inserted through respective opening 1210 a, 1210 b of outer sleeve 1206, across flattened portion 1280 of trocar assembly 1270 and into receptacle 1320 b, 1320 a of the other retention member 1300 b, 1300 a, respectively. That is, extension portion 1310 a of retention member 1300 a is inserted through opening 1210 a (or 1210 b) of outer sleeve 1206, across flattened portion 1280 and into receptacle 1320 b of retention member 1300 b, and extension portion 1310 b of retention member 1300 b is inserted through opening 1210 b (or 1210 a) of outer sleeve 1206, across flattened portion 1280 and into receptacle 1320 a of retention member 1300 a. The engagement between extension portion 1310 a, flattened portion 1280 and receptacle 1320 b, and the engagement between extension portion 1310 b, flattened portion 1280 and receptacle 1320 a is configured to prevent longitudinal translation of a trocar member 1274 of trocar assembly 1270 with respect to outer sleeve 1206 of trocar assembly 1200 (e.g., due to the engagement between extension portions 1310 a, 1310 b and walls 1282 of flattened portion 1280). Additionally, the engagement between extension portion 1310 a, flattened portion 1280 and receptacle 1320 b, and the engagement between extension portion 1310 b, flattened portion 1280 and receptacle 1320 a is configured to prevent relative rotation between trocar member 1274 of trocar assembly 1270 and outer sleeve 1206 of trocar assembly 1200.

Additionally, and with particular reference to FIG. 50, each retention member 1300 a, 1300 b includes a nub 1302 (only nub 1302 associated with retention member 1300 a is shown), which is configured to mechanically engage a detent 1284 of trocar assembly 1270. It is envisioned that the engagement between nubs 1302 and detents 1284 helps maintain the proper alignment and/or orientation between retention members 1300 a, 1300 b and trocar assembly 1270.

To disengage retention members 1300 a, 1300 b from each other, it is envisioned that a user can use a tool (e.g., a screwdriver-type tool) to push extension portions 1310 a, 1310 b out of receptacles 1320 b, 1320 a, respectively. It is also envisioned that retention members 1300 a, 1300 b are configured to be tool-lessly disengaged from each other and from trocar assembly 1270. Disengagement of retention members 1300 a, 1300 b allows trocar assembly 1270 to be removed from outer sleeve 1206 of trocar assembly 1200 (e.g., for replacement or cleaning). It is envisioned that cleaning can occur by inserting a cleaning device at least partially within at least one opening 1210 a, 1210 b of outer sleeve 1206 of extension assembly 1200, and directing a cleaning fluid (e.g., saline) proximally and/or distally to help flush out any contaminants that may be present within outer sleeve 1206, for example.

Additionally, while extension assembly 1200 and trocar assembly 1270 are shown used in connection with adapter assembly 100, the present disclosure also envisions the use of extension assembly 1200 and/or trocar assembly 1270 with a surgical instrument (e.g., a circular stapling instrument) without the use of an adapter assembly.

With reference to FIGS. 53-55, the present disclosure also includes a strain gauge 1500, a position sensor 1520, and a memory sensor 1540 (e.g., an E-PROM (erasable programmable read-only memory) sensor). With particular reference to FIG. 55, it is envisioned that a flexible cable 1600 extends between strain gauge 1500, position sensor 1520, memory sensor 1540 and a printed circuit board (not shown), and from the printed circuit board to an electrical connector disposed at proximal portion 302 of adapter assembly 300, for example.

It is envisioned that strain gauge 1500 is used to detect an axial load exerted on the tissue during clamping of tissue. Here, it is envisioned that if this load is too great, or exceeds a predetermined value, the user (or stapling device 10 itself) may abort the stapling operation or may choose to use a different stapling device 10 or adapter assembly 100, for example.

It is envisioned that position sensor 1520 is used to detect the axial position of the fasteners during the stapling process (e.g., when the fasteners are being ejected from adapter assembly 100). It is further envisioned that memory sensor 1540 is configured to recognize the size and/or type of staple cartridge that is engaged with adapter assembly 100 that is engaged with stapling device 10 and to relay this information to handle housing 12 of stapling device 10.

Any of the components described herein may be fabricated from either metals, plastics, resins, composites or the like taking into consideration strength, durability, wearability, weight, resistance to corrosion, ease of manufacturing, cost of manufacturing, and the like.

Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. 

What is claimed is:
 1. An adapter assembly for operably connecting an end effector to an electrosurgical instrument, the adapter assembly comprising: a drive transfer assembly including first, second, and third rotatable shafts; a first pusher assembly operably connected to the first rotatable shaft for converting rotational motion from the first rotatable shaft to longitudinal movement to perform a first function; a second pusher assembly operably connected to the second rotatable shaft for converting rotational motion from the second rotatable shaft to longitudinal movement to perform a second function; a drive member operably connected to the third rotatable shaft for transferring rotational motion from the third rotatable shaft to perform a third function; an extension assembly operably connected to a distal end of the adapter assembly, the extension assembly including at least one flexible band assembly operably connected to one of the first and second pusher assemblies; a trocar assembly configured for releasable engagement with the extension assembly; a first retention member configured to releasable couple the trocar assembly with the extension assembly; and a second retention member configured to releasably couple the trocar assembly with the extension assembly, the first retention member configured to engage the second retention member.
 2. The adapter assembly of claim 1, wherein each of the first retention member and the second retention member is configured to engage a flat portion of the trocar assembly.
 3. The adapter assembly of claim 1, wherein the second retention member is configured to engage the first retention member.
 4. The adapter assembly of claim 3, wherein each of the first retention member and the second retention member is configured to engage a flat portion of the trocar assembly.
 5. The adapter assembly of claim 1, wherein the first retention member includes a nub configured to releasably engage a respective detent of the trocar assembly.
 6. The adapter assembly of claim 1, wherein the extension assembly defines a longitudinal axis, and wherein the first retention member is movable in a direction perpendicular to the longitudinal axis through an opening of the extension assembly and into engagement with the trocar assembly.
 7. An electromechanical circular stapling instrument, comprising: a handle assembly; an elongated portion extending distally from the handle assembly and defining a longitudinal axis; a trocar assembly including a distal tip for penetrating tissue, the trocar assembly configured for releasable engagement with the elongated portion; and a first retention member and a second retention member configured to releasably couple the trocar assembly with the elongated portion, each of the first retention member and the second retention member configured to engage a flat portion of the trocar assembly, and wherein the first retention member is configured to engage the second retention member.
 8. The electromechanical circular stapling instrument of claim 7, wherein the second retention member is configured to engage the first retention member.
 9. The electromechanical circular stapling instrument of claim 7, wherein each of the first retention member and the second retention member includes a nub configured to releasably engage a respective detent of the trocar assembly.
 10. The electromechanical circular stapling instrument of claim 7, wherein each of the first retention member and the second retention member is movable in a direction perpendicular to the longitudinal axis through an opening of the elongated portion and into engagement with the trocar assembly.
 11. A surgical instrument, comprising: an elongated portion defining a longitudinal axis; a trocar assembly configured for releasable engagement with the elongated portion; a first retention member configured to releasably couple the trocar assembly with the elongated portion; and a second retention member configured to releasably couple the trocar assembly with the elongated portion, wherein the first retention member is configured to engage the second retention member.
 12. The surgical instrument of claim 11, wherein the first retention member is configured to engage a flat portion of the trocar assembly.
 13. The surgical instrument of claim 12, wherein the second retention member is configured to engage a flat portion of the trocar assembly.
 14. The surgical instrument of claim 11, wherein a portion of the first retention member is configured to move from a first lateral side of the longitudinal axis, through an opening of the elongated portion, and to a second lateral side of the longitudinal axis.
 15. The surgical instrument of claim 14, wherein a portion of the second retention member is configured to move from the second lateral side of the longitudinal axis, through the opening of the elongated portion, and to the first lateral side of the longitudinal axis. 